One vertex per element, one color per generator, with an edge from x to x·s.
(1,2,5,4)(3,7,8,6)(9,10)(11,15)(12,16)(13,17)(14,18)(19,26)(20,34)(21,29)(22,28)(23,27)(24,33)(25,31)(30,36)(32,38)(35,40)(37,39)(1,3,5,8)(2,6,4,7)(9,11)(10,15)(12,23)(13,22)(14,21)(16,27)(17,28)(18,29)(19,30)(20,24)(25,37)(26,36)(31,39)(32,40)(33,34)(35,38)(9,12)(10,16)(11,20,21,23)(13,25)(14,24)(15,27,29,34)(17,31)(18,33)(19,32)(22,35,36,37)(26,38)(28,39,30,40)(1,4,5,2)(3,6,8,7)(10,17)(13,26)(15,28)(16,31)(18,19)(22,36)(25,38)(27,39)(29,30)(32,33)(34,40)(35,37)A Cayley diagram is a choice, not a fact about the group. Another drawing of this group — in a book, or on a different generating set — may look nothing like this one.